Method of manufacturing platinum-containing catalyst



Patented Dec. 30, 1952 CONTAINING CATALYST Vladimir meme, Hinsdale,,lll., assignor toUniversal Oil Products Company; Chicago; 111., a

corporation of Delaware No Drawing, Application April 12, 195 1, Serial. No. 220,740.

15 Claims.

This invention relates to a reforming process and to the manufacture of catalysts for use therein. This application is a continuation-inpart of my earlier applications Serial No. 60,381, filed November 16, 1948, now Patent No; 2,611,736, September 23,1952, and Serial No. 14.2,3'5l, filed February 3, 1950, now abandoned.

The term reforming is well known in the petroleum industry and refers to the treatment of gasoline fractions to improve the anti-knock characteristics thereof. The gasoline fraction may be a full boiling range gasoline having" an initial boiling point within the range of from about 50 to about 100 F. and an end boiling point within the range of from about 350 to 425 F. or more, or it may be a selected fraction thereof which usually will be a higher boiling iractiomcommonly referred to as naphtha, and generally will have an initial boiling point 'of from about 150 to about 250 F. and an end boiling point within the range of from about 350 to 425 F. or more.

The presentv invention is particularly applicable to the reforming of straight run gasolines' which contain naphthenic hydrocarbons, and

parafiinic hydrocarbons which usually are of straight chain or slightly branched chain structure, as well as varying proportions of aromatic hydrocarbons. The invention is also applicable to the reforming of cracked gasolines and par-'1 ticularly thermally cracked gasoline, either alone or in admixture with straight-run gasoline. In I order to obtain best results in reforming opera-.

tions, it is desired to dehydrogenate the naphthenic hydrocarbons to produce aromatics, to cyclisi'ze the straight chain paraffinic hydrocarbons to form aromatics, as well as to effect a cracking will result in a product of improved.

anti-knock characteristics. In general, the lower molecular weight products. have higher octane numbers, and thus a final gasoline product of lower average molecular weight will usually have a higher octane rating. Further, during the cracking reaction, isomerization or other molecular rearrangement occurs which also results in products having higher anti-knock characterisadvantage when the charging stock contains components'boiling above about 400 F; in order to convert. these components to fractions boiling' below about 400 F. It is thus seen that the selective cracking results not only inan improved quality productibut also" in'an increasein quan tityv of. the desired products.

However; the crackingmustbe selective and .must' not result in the decomposition of thenormany liquid" hydrocarbons substantially or com- All pletely into normally gaseous hydrocarbons. The

desired selective cracking. generally'comprises the splitting of a higher" boiling hydrocarbon molecule into two" molecules" both of which are nor mally liquid hydrocarbons,- Toa lesser extent it comprises the'rer'noval of methyl, ethyl and-propyl groups which, in the presence' of hydrogen, are converted tomethane; ethane and propane. However, the removal of these radicals is controlled so that notmore than one or possibly two of suchradicals are removed from a given molecule. Forexample; in the presence of hydrogen, decane maybe" reduced to two pentane" molecules, h'eptan'ejto hexanejnonane t'o' octane or heptane, etc. O'n the other'han'd; uncontrolled or nonselective' cracking will result in the decomposition of normally liquid" hydrocarbons into normally gaseous hydrocarbons as;;for"example, by the continued demethylation of normal heptane to produce 'l methyl'groups which, in theprese'nce of hydrogen, are'converted to methane.

Another important objection to non-selective or uncontrolled cracking isthat this" type of cracking will'result in" the more rapid formation of 'larger quantities'o-fcokeorcarbonaceous material"whichdeposits on the'catalyst and decreases' -or destroys its" activity to "catalyze the desired reactions. This in turn results in shorter processingcycles orperiods, with the necessity of more-fre'quentregeneration of thecatalyst by burning the carbonaceous productsther'efrom or,

should the catalyst activity be" destroyed, it will be necessary to shut down'the unit to remove the old catalyst and replace it with new catalyst.

Another important feature in suc'cessfulreforming processes is the matter'of hydrogen production andjcon's'umption. Investigation" has shown thatithe presence of hydrogen in the reforming zone further" tends" to decrease the amount of carbonaceous deposit on the catalyst. In view ofthe fact that the cost of hydrogen is quite'high', itjis essential that. there be no net consumptionlof hydrogenor, in other words, at least as much" hydrogen must be produced in the ties; The selective cracking is also of'particular 55 process as is consumed therein.

In one embodiment the present invention relates to a process for reforming a gasoline fraction which comprises subjecting said gasoline fraction to contact at reforming conditions with a catalyst prepared by compositing latinum with a support in the presence of a basic compound.

In a specific embodiment the present invention relates to a process for reforming a gasoline fraction which comprises subjecting said gasoline fraction to contact at reforming conditions with a catalyst prepared by compositing platinum with a support in the presence of ammonium hydroxide.

In another specific embodiment the present invention relates to a process for reforming a gasoline fraction which comprises subjecting said gasoline fraction to contact at reforming-conditions with a catalyst prepared by compositing' platinum with alumina in the presence of ammo: nium hydroxide.

In a more specific embodiment the present invention relates to a process for reforming a gasoline fraction which comprises subjecting said fraction to contact at reforming conditions with a catalyst prepared by combining a halogen with alumina in an amount of from about 0.1% to about 8% by weight of said alumina on a dry basis, commingling therewith'an aqueous solution of a platinum compound anda water soluble basic compound in an amount to form a final catalyst containing from about 0.01% to about 1% by weight of platinum.

In another more specific embodiment the present invention relates to a process for reforming a gasoline fraction which comprises subjecting said fraction to contact at reforming conditions with a catalyst prepared by combining a halogen with alumina in an amount of from about 0.1% to about 8% by weight of said alumina on a dry basis, commingling therewith a platinum compound-ammonium hydroxide solution in an amount to form a final catalyst containing from about 0.01% to about 1% by weight of platinum.

In another specific embodiment the present invention relates to a process for reforming a straight run gasoline fraction which comprises subjecting said gasoline fraction to contact at a temperature of from about 600 to 1100 F., a pressure of from about 50 to about 1000 pounds per square inch and weight hourly space velocity of from about 0.1 to about in the presence of the catalyst as herein set forth.

-In still another embodiment the present invention relates to a method of manufacturing a catalyst which comprises compositing platinum with a support in the presence of a basic compound.

In another specific embodiment the present invention relates to a method of manufacturing catalyst which comprises combining a halogen with a support in an amount of from about 0.1%

to about 8% by weight of said support on adry' basis, commingling therewith an aqueous solution of a platinum compound in a water soluble basic nitrogen-containing compound in an amount to form a final catalyst containing from about 0.01% to about 1% by weight of platinum, and heating the composite in air at a temperature of from about 500 to about 1100 F.

In still another specific embodiment the resent invention relates to a method of manufacturing a catalyst which comprises combining a halogen with alumina in an amount of from about 0.1% to, about 8% by weight of said alumina on a dry basis, forming said alumina-halogen composite into particles of uniform size and shape, calcining said particles at a temperature of from about 800 to about 1400 F., commingling with the calcined particles a platinum compound-ammonium hydroxide solution in an amount to form a final catalyst containing from about 0.01% to about 1% by Weight of platinum, and heating the resultant composite in air at a temperature of from about 500 to about 1100 F.

The use of platinum as a catalyst for conversion processes has been of limited commercial acceptance because of the high cost of the catalyst. The present invention is based on the discovery that exceptionally good catalysts may be prepared to contain low concentrations of platinum. Whil these catalysts may contain larger concentrations of platinum, which may range up to about 10% by Weight or more of the alumina, it has been found that exceptionally good catalysts may be prepared to contain as low as from about 0.01% to about 1% by weight of platinum. Catalysts of these low platinum concentrations are particularly preferred in the present invention because of the considerably lower cost of the catalyst. It is well known that platinum is expensive and any satisfactory method of reducing the amount of platinum considerably reduces the cost of the catalyst and thus enhances the 'attractiveness of the catalyst for use in commercial proc-- esses.

Alumina is a particularly preferred support for compositing with the platinum because it appears to show improved advantages for use as a supporting component for the lOW platinum concentrations, apparently due to some peculiar association of the alumina with the platinum, either as a chemical combination or as a physical association. It has been found that the combination of alumina and low platinum concentration is a very active catalyst and also has a long catalyst life; that is, the catalyst retains its high activity for long periods of service. After these long periods of service, the catalyst may show a drop in activity and it further has been found that the particular combination of alumina and platinum renders the catalyst susceptible to ready regeneration.

The novel method of compositing platinum also may be used with other supports including silica, zinc oxide, magnesia, zirconia, thoria, etc. as well as supports comprising two or more components such as silica-alumina, silicamagnesia, silicazirconia, silioa-thoria, silica-zinc oxide, silicaalumina-magnesia, silica-alumina-zirconia; silica-alumina-thoria, etc. The use of the basic compound in compositing platinum with the support offers improved advantages in uniformly distributing the plati-' num throughout the support which in turn ofiers advantages in the reforming process as hereinafter will be set forth in detail.

As an essential feature of the present invention, impregnation of the support must be effected in the presence of a basic compound. A particularly suitable method of impregnation is by means of a solution of a suitable platinum compound. However, it has been found that, unless the impregnation is efiected in the presence of the basic compound, uneven distribution of the platinum in or on the support is obtained. Usually this uneven distribution comprises surface coating; that is, the platinum compound is distributed only on the surface of the particles and not evenly throughout the vmass. By effecting the impregnation, in thepresence ofa basic com-- silica-alumina-zinc oxide,

pound, even distribution of the platinum throughout the support is obtained.

A particularly satisfactory method of impregmating the support comprises the use of an aqueous solution of chloroplatinic acid. In a preferred embodiment, the aqueous solution of chloroplatinic acid is commingled with the basic compound solution and the mixture is added to the support. In another embodiment, the basic compound solution may be added to the support and the chloroplatinic acid solution is thereafter added to the mixture. Instill another embodiment, the chloroplatinic acid solution may be added to the upport and th basi compou oluti n is thereafte add dn ny event. he mixtnre is allowed to s and. prefe ablyw t r after suitablea itating, so that thorou m in is obt ined and e en distribution thro hout the.

support is. effected.

It is understood that any suitable source of platinum may be d i r an e wi h t e present in ent h opl a i ne ally is pr ie d beca it is m e ea l a abl Solutions or"; other platinum-containing compounds may be employed including those of ammonium platinum chloride, trimethylbenzyl ammonium platinum chloride, tetramino platino chloride, ammonium platino nitrate, dinitro diamino platinum, etc. It is understood that, when desired, other than aqueous solutions may b emplo d n s i pa t cu u e h e the platinum compound is not readily water oluble.

hereinbefore set forth, it is an essential feature of thepresent invention that the impregnation of the support with platinum is effected the presence of a basic compound. The preterred basic compound is a nitrogen containing water soluble basic compound. The basic compound should not introduce undesirable impurities into the final catalyst. A preferred basis compound for use in accordance with the present invention comprises ammonium hydroxide. Other basic compounds comprise aqueous solutions of organic amino compounds such as the alkylene polyamines including ethylene diamine, propylene triamine, butylene tetramine, etc, ess-ammo compounds including methyl amine, ethyl amine, diethyl amine, triethyl amine, propyl amine, dipropyl amine, butyl amine, aniline, etc., alkanol amines, including ethanol amine, propanel amine, butanol amine, diethanol amine, triethanol amine, etc. Other satisfactory organic amino compounds include hexamethylene tertramine, hexamethylene diamine, etc.

which may be used in accordance with the present invention comprises basic ammonium compounds including ammonium carbonate, am-

monium bicarbonate, ammonium carbamate, ammonium citrate, ammonium aluminate, am-.

monium propionate, ammonium butyrate, etc. In some cases, it may be desired to coinmingle ammonia with these solutions in order to insure definite basicity. As another alternative but not necessarily equivalent method, ammonium nitrate, ammonium acetate, aluminum nitrate, aluminum acetate, etc. may be employed in adwith ammonium hydroxide in a suficient concentration to form a basic solution. It is understood that the various basic compounds are not necessarily equivalent. In any event, the basic compound employed must not leave an undesired residue on the catalyst.

The use of abasic compound is differentiated from th e use of an acidiccompound as, for ex- Another suitable class of basic compounds I ample, ammonium chloride. Ammonium chloride cannot be used because, upon commingling of ammonium chloride With chloroplatinic acid, a precipitate of ammonium chloroplatinate is obtained. Even upon heating or upon the addition of a basic compound, the precipitate will not be dissolved to form a clear solution. However, in some cases, both the addition of a basic compound and heating will dissolve the precipitate to form a-clear solution and, in such cases, the use of ammonium chloride may be employed in conjunction with both the basic compound and heating.

With proper selection of the chloroplatin-ic acid solution and of a basic ammonium compound solution, commingling of these solutions will not form a precipitate and, therefore, will not form ammonium chloroplatinate. Applicant is not certain as to the exact chemical formula of the compound formed but it is believed to be a hydrolysis product of [Pt(NHs) 2C121C12. In any event it is apparent that the clear solution formed upon the mixing-"of a basic ammonium compound solution with chloroplatinic acid solution is different from the ammonium chloroplatinate precipitate formed upon the addition of ammonium chloride to chloroplatinic acid solution. If ammonium chloroplatinate is formed, as hereinbefore set forth, or due to the use of a too highly concentrated solution of chloroplatinic acid, the ammonium chloroplatinate may be redissolved to form the clear solution which is no longer ammonium chloroplatinate and apparently is the compound hereinbefore set forth. The difference between the two compounds is further evidenced by the fact that the addition of carbonate ions, as by the addition of sodium carbonate, will not form a precipitate in the case of the mixture of ammonium chloride with chloroplatinic acid upon heating, but will form a precipitate in the case of the solution of ammonium hydroxide with chloroplatinic acid upon heating.

In a preferred embodiment of the present invention, the final catalyst contains halogen in a specific concentration. It has been found, and will be shown in the following examples, that the presence of halogen within a specific range effects a considerable improvement in the catalyst. It is believed that the halogen enters into some chemical combination or loose complex with the support and/or platinum, and therebycined, preferably in the presence of an oxygen-- containing gas, particularly air, at a temperaturev of from about 500 to about 1100 F. for a period of from about 1 to 12 hours or more. Calcin-ation in the presence of air appears to result in a final gasoline product of higher octane number than is obtained when the catalyst is calcined only in the presence of a reducing atmosphere. In still another embodiment of the invention the final composite may be reduced in the presence of hydrogen and then calcined in the presence of air, both the reduction, and the calcination being 7 effected at a temperature of from about 500 to about 1100 F.

In one embodiment of the invention the support is formed into particles of uniform size and shape prior to compositing the platinum therewith. In this embodiment of the invention, the particles of uniform size and shape are subjected to calcination at a temperature of above about 800 F. and preferably within the range of from about NO to about 1400 F. for a period of from about 1 to 8 hours or more. The temperature and time of heating are correlated; that is, shorter times are employed with higher temperatures and longer times are employed with lower temperatures. On the other hand, the final composite containing platinum compound should not be heated at a temperature above about 1100 F. and preferably is calcined in air at a temperature of from about 530 to about 1100 F. for a period of from about 1 to 12 hours or more as hereinbefore set forth. In another embodiment of the invention the platinum is composited with the support while the latter is in a wet condition or after only partial drying thereof. In still another embodiment of the invention, the support may be formed into particles of uniform size and shape and the platinum is composited therewith before the support is subjected to partial or substantially complete drying.

A preferred method of preparing alumina is to commingle a suitable reagent, such as ammonium hydroxide, ammonium carbonate, etc. with a salt of aluminum such as aluminum chloride, aluminum nitrate, aluminum acetate, etc. in an amount to form aluminum hydroxide which, upon drying is converted to alumina. In the interest of simplicity, the aluminum hydroxide is referred to as alumina in the present specification and claims in order that the percentages are based on the alumina free of combined water. found that aluminum chloride is generally preferred as the aluminum salt, not only for convenience in subsequent washing and filtering procedures, but also because it appears to give best results.

After the alumina has been formed, it is generally washed to remove soluble impurities. Usual washing procedures comprise washing with water, either in combination with filtration or as separate steps. It has been found that filtra tion of the alumina is improved when the wash water includes a small amount of ammonium hydroxide. The severity of washing will depend upon the particular method employed in preparing the catalyst. In one embodiment of the invention, the alumina is thoroughly washed with a suitable amount of water and preferably water containing ammonium hydroxide to reduce the chlorine content of the alumina to below about 0.1%. In another embodiment of the invention this washing may be selective to retain chlorine in an amount of from about 0.2% to about 8% by weight of the alumina on a dry basis. In accordance with this method of preparing the catalyst, the chlorine is obtained from the original aluminum chloride and is retained in the alumina,

thus avoiding the necessity of adding the halogen in a later step of catalyst preparation. However, it generally is difficult to control the washing procedure to retain exactly the desired amount of halogen and, for this reason, it usually ispreferred to wash the alumina to remove substantially all of the chlorine and thereafter add the halogen in a controlled amount. The addrtion of the halogen in this manner permits better It has been 8. control of the amount of halogen being added. In another embodiment of the invention, the washing may be selective to retain the chlorine in an amount constituting a portion of the total halogen desired, and the remaining portion of the halogen is then added in a subsequent step. In this method, the halogen may comprise the same halogen or a mixture of two different halogens as, for example, chlorine and fluorine.

Alumina prepared in the above manner, after washing and filtration, is generally recovered as a wet cake. In a preferred embodiment of the present invention, the halogen, when added, is introduced at this stage of the catalyst preparation, the composite is dried to reduce the same to a moisture content of about 30%, which generally requires drying at a temperature of from about 200 to about 500 F. for a period of from about 2 to 24 hours or more. In one embodiment the composite is formed into particles of uniform size and shape as by pilling, extrusion or other.

suitable methods. In another embodiment, the alumina may be formed into particles of uniform size and shape and the halogen thereafter added. In still another embodiment the halogen and/or platinum addition may be effected prior to forming the composite into particles of uniform size and shape.

Silica may be prepared by reacting a suitable,

acid such as sulfuric acid, hydrochloric acid, etc. with an alkali metal silicate and particularly water glass under conditions to precipitate silica;

In another embodiment of the invention the sili' ca may be prepared as substantially spheroidal gel particles by dropping a suitable mixture ofv acid and alkali metal silicate into a bath of water immiscible suspending medium, such as hydrocarbon oil, the depth and temperature of the suspending medium being controlled so that droplets form into spheroidal particles during passage through the suspending medium. In one embodiment a layer of water may be disposed beneath the oil suspending medium, and the spherical particles may be withdrawn by means of a circulating stream of water from the forming zone into suitable washing, drying and/or calcining equipment as desired. When the support comprises other metal oxides as hereinbefore set forth, they may be prepared in any suitable manner, including the formation of spherical particles. In another embodiment, when the support comprises two or more components, they may be prepared by separate, suc

cessive or conjoint precipitation or gelation. It is understood that the detailed description set forth in connection with the preparation and further handling of alumina also may apply to the other supports.

Regardless of the stage of catalyst preparation at which the halogen is added, the halogen may added as an aqueous solution for ease in handling and for control of the specific amount to be added. Another satisfactory source to be used for adding the halogen is the volatile salts, such as ammonium fluoride, ammonium chloride, etc. I The ammonium'ions will be removed during the Hydrogen fluoride is preferably subsequent heating of the catalyst and, titers tore, Will not leave undesir ble deposits; the catalyst. In still anot er method, t e alogen may be added as fluorine, chlorine, bromine or iodine but, in View of the fact that the halogens are normally more cilifilcult to handle, it generally is preferable to utilize them the form or 91 solution for ease in handling. In some cases, the inclusion of certain componentswill not be harm'- ful but may be beneficial, and in these cases the halogen may be added in the form of suitable salts.

The concentration of halogen in the finished catalyst will be Within the range of from about 0.1% to about 8% by weight of the'suppoft-on a dry basis. Fluorine appears to be more active and, therefore, will be used within the raii feof from about 0.1% to about- 3% by Weight of the supporton a dry basis. Chlorine' 'tvill be used Within the range of from about 0.2 to about 8% and preferably from aboutos to ahdil't 5% by Weightof the support on iidry basis. It appears that halogen concentrations-below these wwr limits do not give the desired improvemefitand, on the other hand, concentrations of halo'g'efi above the upper limits adye'r'se'ly affect the" s'elctivity' of the catalyst, thus catalyzing side r'eac: tions to an extent greater than de'sifd'; I I 1 As hereinbefore set forth, it is essential that the platinum compound be incorporated in the support in the presence of a basic compound to obtain uniform distribution or the platinum throughout the catalyst mass. In one emu-out: merit of the" present invention the support, either with or without halogen, is formed into particles of uniform size and shape price to the addition of the platinum compound- When the s'l l o'rt is to be form-ed into particle's of uniform size and shape by Filling, the Support, with or" Without halogen, is dried at a temperature of fromabout 200" to about 500 F. for a'period of from about 2 to 24- hours or more. The partially dried cake is ground and a suitable lubricant is added, such as stearic acid, rosin, hydrogenated coconut oil, graphite, etc, after which the composite is formed into pills in any suitable pelleting machine. Particularlysatisfactory particles comprise cylindrical pills of a size ranging from about X 9g to A" x /4" or thereabouts. Pills of uniform size and shape may also be formed by extrusionor' other suitable methods. As hereinbeforeset forth, the pills, prior to the addition of the" platinumcompound may be calcined at a tent: perature above 800 F. In some cases, the lubricant will be removed duringthe high temperature heating. In other cases as, for example. when graphite is used as the lubricant, the separate" high temperature heating step maybeomitted, and the effective heat treatment of the catalyst may be obtained in the plant before or durin processing of the hydrocarbons.

In accordance with the invention, the support is" impregnated with a platinum c'ompound b'asic' compound solution in order to obtain evn' distribution of the platinum compound throughout" 10 monium hydroxide solution were of the same color throughout, Whereas the pills impregnated in the absence of ammonium hydroxide were of a dark color on the outside and of a light color on the inside.

A possible explanation of the benefits obtained with the evenly distributed catalyst pills is that the platinum molecules are spread throughout the pills and therefore are spaced further apart and will not result in the formation of large crystals of platinum. On the other hand, in the surface coated pills, the platinum molecules are spaced closer together and, therefore, may form large crystals. Another advantage to the even distribution of the platinum throughout the catalyst is that the platinum in association with the hydrogen tends to reduce carbon formation and thus when the platinum is distributed evenly throughout the catalyst this effect is enhanced. On the other hand, when the platinum comprises only surface coating, the center of the p111 may catalyze carbon formation because of not bein able'to benefit from the tendency of the platinum and hydrogen to reduce carbon formation.

Another important advantage to the even distribution of platinum throughout the catalyst from a commercial viewpoint is that a smaller Volume of catalyst is required for a given plant capacity than in the case of the surface coated pills. This reduces the cost of the plant equipinent by permitting the use of, smaller yessels and reduced supporting structures, as well as lower catalyst shipping charges, etc. As applied to the impregnation of preformed particles, it is advantageous to incorporate the platinum compound at the later stages (if catalyst preparation inordi' that platinum Will not be lost during subsequent handling and treating of" the catalyst. Thus, much of the fiecessaryrhixing, Washfiltering'and' heatin'g'stps is done before the platinum compound is incorporated. Further. this permits effecting the desired" high temperature heating ofthe support particles at temperatures aboi e'IIOO" F. Without also subjecting the composite containing'platinum to these high temperatures; 0 p

As' here'ir'ib'efore' set forth, impregnation of the support with the p atinum compound is effected in the presence of" a compound solution and, in a preferred embodiment, an aqueous solution of chl'ofoplatifiic acid is comming'led with a basic compound solution in proportions to form a: n'g'ixeu soluti n havifig a pH within the range or from about 5 to abo t 10 and preferably within the range of from about 8' to about 1 0. This mixture is then ccm'mi'r'igld iivith the support inthe manner hcr'eiribefore set forth or, in another embodiment of the invention, the basic compound solution or the chloi'cplatini'c acid solution may be added to the support and the other solution subsequently added thereto.

Regardless of the order of adding the basic compound and chloroplatinic acid solutions, a particularly advantageous method of cumming'ling the solutions with the support particles is" to soak'the support or the support-halogen particles in an aqueous solution of chloroplatinic pound; In another embodiment of the invention,

the; particles are soaked in an" aqueous solution ofchloroplatinic'ac'id andbasic compound, and

7'5 the Water and residual basic compound are removed by decantation, filtering or the like.

In this'embodiment of the invention, the chloroplatinic acid solution is preferably utilized as a hot solution.

After the chloroplatinic acid solution has been incorporated in the support and the water and residual basic compound removed therefrom, the composite is dried at a temperature of from about 200 to about 500 F. fora period of from about 2 to 24 hours or more, and the composite is then calcined in air at a temperature of from about 500 to about 1100 F. In still another embodiment of the invention, the composite after drying the platinum compound has been added thereto,

the mass is dried at a temperature of about 200 to 500 F. for a period of from about 2 to 24 hours or more and then calcined at a temperature not to exceed 1100 F. 1

Although the catalyst of the present invention will have a long life, it may be necessary to regenerate the catalyst after long periods of service. The regeneration may be effected by treatment with air or other oxygen-containing gas to burn carbonaceous deposits therefrom. In general, it is preferred to control the regeneration temperature not to exceed 1100 F. and preferably the regeneration is effected at a temperature within the range of from about 600 to about 800 F.

The reforming process will be effected at a temperature within the range of from about 600 to 1100 F., a pressure within the range of from about 50 to about 1000 pounds or more per square inch and at a weight hourly space velocity of from about 0.1 to about 20. The weight hourly space velocity is defined as the weight of oil per hour per Weight of catalyst in the reaction zone.

Hydrocracking reactions are favored at (temperatures within the range of from about 600 to about 700 F. and at pressures within the range of from about 500 to about 1000 pounds or more. Hydrorcracking is defined as cracking or splitting of carbon bonds accompanied by saturation of the fragments so formed by hydrogen present in the reaction zone and, in accordance with the present invention, the hydrocracking will be selective both in quality and in quantity as hereinbefore set forth. On the other hand, aromatization reactions are favored at temperatures within'the range of from about 650 to about 1100? F. and at lower pressures within the range of from about 50 pounds to about 400 pounds per square inch.. It is an essential feature of the present invention that the temperature, pressure and space velocity are correlated to produce the desired aromatization and selective hydrocracking. The exact temperature, pressure and space velocity to be used. in any given operation will depend upon the particular gasoline fraction being treated and the particular products desired.

In one embodiment of the process, sumcient hydrogen will be produced in the reforming reaction to furnish the hydrogen required in the process and, therefore, it may be unnecessary to either introduce hydrogen from an extraneous source or to recycle hydrogen Within the process. However, it usually will be preferred tointroduce hydrogen from an extraneous source, generally at the beginning of the operation, and to recycle hydrogen within the process in order to be assured of a sufficient hydrogen atmosphere in the reaction zone. The hydrogen present in the reaction zone generally will be within the range of from about 0.1 to about 10 mole of hydrogen per mol of hydrocarbon. In some cases the gas available for recycling will contain hydrogen sulfide, introduced with the charge or liberated .from the catalyst, and it is within the scope of the present invention to treat the hydrogen containing gas to remove hydrogen sulfide or other impurities before recycling the hydrogen within the process.

While the catalysts of the present invention are particularly desirable for use in reforming processes, it is Lmderstood that these catalysts may be used in any process for which platinum is a catalyst. These catalysts also may be effective for eifecting hydrogenation of unsaturated aliphatic hydrocarbon re fiflix catail'ysts' ifi ay e use u f8? effecting the cracking of normally gaseous or normally liquid hydrocarbons to produce lower boiling hydrocarbons, dehydrogenation of normally gaseous or normally liquid organic compounds to form the corresponding unsaturated compounds, etc. Other reactions in which these catalysts may find usefulness include oxidation as, for example, oxidation of olefins to form the corresponding oxides, such as the oxidation of eth 1cm ethylene oxide, mmmmpypfitfifi, etc., 0x1 timohols, ketones, etc. These and other oxidation reactions per se are Well-known in the art and it is within the scope of the pres ent invention to effect these reactions in the presence of these lcatalysts. In reactions involv-' ing hydrogenation, oxidation or condensation, it is preferred that the halogen content of the catalyst be within the lower limits of the ranges hereinbefore specified in order to minimize side reactions.

The process of the present invention may be effected in any suitable equipment. A particularlysuitable proces comprises the well-known fixed bed system in which the catalyst is disposed in a reaction zone and the hydrocarbons tobe treated are passed therethrough in either upward or downward flow. The products are fractionated to separate hydrogen and to recover the desired products, As hereinbefore set forth, the hydrogen preferably is recycled for further use in the process. Other suitable units in which the process may be eifectedinclude the fluidized type process in which :the hydrocarbons and catalyst particles are maintained in a state of turbulence under hindered settling conditions in a reaction zone, the compact moving bed type in which particulated catalyst and the hydrocarbons are passed either concurrently or countercurrently to each other, and the suspensoid type of operation in which particulated catalyst is carried into reaction zone as a slurry in the hydrocarbon oil.

The following examples are introduced to further illustrate the novelty and utility of the present invention, but not with the intention of unduly limiting the same.

EXAMPLE I A catalyst was prepared in accordance with the present invention by adding ammoniumhy .13 droxide to aluminum chloride hexahydrate to form aluminum hydrate. The resultant aluminum hydrate was washed very thoroughly in order "to reduce the chloride content to below '0.1%by weight on a dry basis. This washing entailed six'separate washes with large amounts of water containing a small amount of ammonium hydroxide and a final wash with water, with intervening filtering between washes. An aqueous solution of hydrogen fluoride was added to the washed alumina in an amount of about 0.3% by weight ofthe alumina on a dry basis. The'a'lumina-fluorine composite was dried at a temperature of about 340 F. for 8-10 hours in orderto reducethe moisture content to about 30%. The partially dried alumina was ground, stearic acid added as lubricant, and then pilled in a Stokes pelleti'ng machine to form cylindrical pills of 93" x in size. The pills were calcined in air at a temperature of about 932 F. 'for 6'hours'to remove thelubricant and then further calcined at a temperature of about 1200 F. for 3 hours. Concentrated ammonium hydroxide solution (30%) was added to a dilute solution of chloroplatinic acid (0.1 gram of chloroplatinic acid in cc. of water) in proportions to form a mixture having a pH of about '9. This solution produced noprecipitate but remained a clear yellow solution. The alumina pills were soaked in the chloroplatinic acid-ammonium hydroxide solution, the quantities being controlled to form a final catalyst containing 0.3% by weight o'fplatinum. The mixture was then heated-on a steam bath, after which the catalyst was dried at 230 F. for 3 hours and calcined in air at 932 F. for 3 hours.

Thiscatalyst was used in a series of threeruns for the reforming of a Mid-Continent straightrun naphtha having a'boiling range of 'from'180 to 400 F., at a temperature of about 850 'F., a pressure of '50'0pounds per square'inch, a weight hourly space velocity of about? and a hydrogen to hydrocarbon molal ratio of 3 :1. The results ofthese runs are indicated in the following table.

Table 1 Days 7 Charge Catalystl Reformate yield, weight percentcf g 3 '3 1. 86:6 F1 octane number (Research 2 34 8 857 Method) "in-"un 858 '1 77.8 FZ-octaue number (A. S. I. M. v 2 34.6 Motor Method). ..i 3 1 47.6 Aromatics, weight percent of charge. 6 6

It will be noted from the above data that catalyst' 1 produced 'a reformate having "a high octane number and of'high aromatic content.

EXAMPLE II of about 2 and ahydrogen to hydrocarbon .molal ratio of 3:1, and gave the results reported in Table-2.

Catalyst 2, Catalyst 3, Calcined at Calcined at 932 F. 1,337 F.

Stabilized reiormatc yield, Volume percent of charge 03.0 77.2 Aromatics, weight percent of charge-.. 88. 9 26. 9 Percent of material boiling below ..2l2 F., based on total liquid product 31 63 It will be noted from the data in the above table that the catalyst calcined after the platinum was composited therewith at a temperature of 1337" F. had decreased aromatization and increased hydrocracking properties as compared to the catalyst calcined at 932 F. This is illustrated in the lower yield, the decrease in arcmatics and in the higher percentage of material boiling below 212 F. As set forth in the present specifications, this amount of hydrocracking is undesirable because it represents .a loss of charging stock to lower boiling material and particularly to gaseous products which cannot be used ingasoline.

EXAMPLE III Another batch of catalyst was prepared in substantially the same manner as hereinbefore set forth. After preparationof the alumina-fluorine pills, the batch was divided into two portions. One portion of the pills was impregnated with chloroplatinic acid-ammonium hydroxide solution and the other portion of the pills was impregnated with chloroplatinic acid solution in the absence of ammonium hydroxide. After final calcination at 932 hydrogen sulfide. was separately passed through each of the two portions and the catalyst pills were split inhali. The pills impregnated in the presence of ammonium hydroxide solution were of a uniform grayish color EXAMPLE IV In. order to. show the effect of fluorine in alumina-platinum catalysts, 'two separate catalysts were prepared, one to contain no fluorine and the other to. contain 1.5% fluorine. These catalysts were used'in separate runs for reforming a Pennsylvania straight-run naphtha having an F2 octanenumber of 41.8, at a temperature of 874 F.'., a pressure of 500 pounds per square inch and -.a weight. hourly space velocity of about'2 in the presence of hydrogen. in the following table:

The results are shown Itwill be noted that the catalyst containing 'iluorine yielded a reformate of 19 octane numbers higher than the catalyst containing no fluorine.

EXAMPLE V Table 4 Catalyst 7,

Catalyst 8, 3% fluorine 6% fluorine i I Catalyst 6, 1.5% fluorine Reforming temperature, F U Reformate yield, wt. I percent of charge.. I F2 octaue number I I an 1 It will be noted that the catalyst containing 1.5% and 3% fluorine gave octane numbers of 78.8 and 77.4 and yields of 83.2% and 85% respectively, Whereas the catalyst containing 6% fluorine gave a much lower yield and a lower octane number gasoline.

EXAMPLE VI The effect of chlorine content on the catalyst is shown in this example, wherein three different catalysts comprising 0.1% platinum on alumina were prepared to contain 0.5%, 1.5% and 3.5% chlorine in the final catalyst. These catalysts were used for the separate reforming of a Pennsylvania straight-run naphtha having a boiling range of from 219 to 339 F. and an F2 octane number of 41.2. The reforming was effected at 872 F2, 500 pounds and a space velocity of about 2 in the presence of hydrogen. The results of these runs are shown in the following table:

Table Catalyst 11,- 3.5% chlorine Catalyst 9,

Catalyst 10, 0.5% chlorine 1.5% chlorine Liquid. volume yield,

wt. percent of charge F2 octane number EXAMPLE VII A catalyst may be prepared in substantially the same manner as described in Example I, but in place of using a chloroplatinic acid-ammonium hydroxide solution, a chloroplatinic acid-ethylene diamine solution may be employed to impregnate the alumina-halogen pills. The platinum will be evenly distributed throughout the alumina in contrast to surface impregnation obtained in the absence of the ethylene diamine.

16 EXAMPLE VIII" A silica-platinum catalyst may be prepared by commingling sulfuric acid with water glass and dropping the resultant mixture into a bath of hydrocarbon oil maintained at substantially atmospheric temperature. A circulating stream of Water is positioned beneath the bath of oil and the silica spheres are transportedto a washing zone wherein soluble impurities are removed. The spheres may be soaked in an aqueous hydrochloric acid solution in order to introduce 0.5% by weight of chlorine based on the dry silica spheres. The spheres are then dried at a temperature of 350 F. for 16 hours and calcined at a temperature of 1200 F. for 4 hours. The spheres then may be soaked in a clear chloroplatinic acid-ammonium hydroxide solution, the quantities being controlled to form a final catalyst containing 0.2% by weight of platinum. The composite then is dried at 250 F. for 6 hours and calcined at 950 F. for 3 hours.

EXAMPLE IX A catalyst may be prepared in substantially the same manner as described in Example VIII but in place of using a chloroplatinic acid-ammonium hydroxidesolution a chloroplatinic acid-propylene triamine solution may be used to impregnate the silica spheres. The platinum will be evenly distributed throughout the silica in contrast to surface impregnation obtained in the absence of the basic compound.

EXAMPLE X A silica-alumina composite is prepared and formed into particles of uniform size and shape. The particles are calcined at a temperature of 1100 F. for 3 hours and then are soaked in an aqueous solution comprising chloroplatinic acid and ammonium carbamate. The platinum concentration is controlled to comprise 0.4% by Weight of the final catalyst.

EXAMPLE XI A silica-magnesia composite is prepared by acidifying water glass with sulfuric acid to form silica gel, Washing'to remove soluble impurities, commingling therewith a slurry of magnesium oxide and intimately mixing the same to form a silica-magnesia composite. An aqueous solution of ammonium hydroxide is commingled with a solution of ammonium platino nitrate, and the resultant mixture is added to the wetmix of silicamagnesia with intimate stirring, following which excess solution is separated, and the resultant mass is dried at a temperature of 350 F. .for 12 hours and then calcined at a temperature of 932 F. for 4 hours. v I

It will be found that impregnating the silicamagnesium support in the presence of the basic compound results in uniform distribution of the platinum throughout the support in contrast to surface coating obtained when the basic compound is not employed.

EXAMPLE XII geese-a 17 chloroplatinic acid-sodium carbonate solution was used as the impregnating medium in the other case (catalyst 13).

When used for the reforming of diiferent samples of a naphtha, these. catalysts gave the results shown in the following table:

It will be noted that the 'catalystprepared using sodium carbonate (catalyst No. 12) yielded a product of only 55.5 octane number, whereas the catalyst prepared using ammonium hydroxide (catalyst No. 13) yielded a product having an octane number of 79.3.

EXAMPLE XIII This example compares the results obtained in reforming operations utilizing different catalysts prepared in the same manner but in one case using chloroplatinic acid-ammonium hydroxide solution (catalyst 14) as the impregnating medium and in the other case using chloroplatinic acid without ammonium hydroxide (catalyst 15).

Different samples of the same gasoline were used as the charging stock for these reforming operations. The reforming in both cases was effected at a temperature of about 850 F., a pressure of 500 pounds per square inch and a space velocity of 2, in the presence of hydrogen in a molal ratio to hydrocarbon of about 3.2.

With platinum concentration of 0.3 by weight in each case, catalyst No. 14 prepared through the use of ammonium hydroxide gave a reformate having an F1 clear octane number of 86.2. Cat-alyst No. 15 prepared without the ammonium hydroxide gave an F1 clear octane number of 80.4. Thus it is seen that the use of ammonium hydroxide resulted in a reformate of 5.8 octane numbers higher than the catalyst prepared without the ammonium hydroxide.

EXAMPLE XIV In another series of reforming runs in a manner similar to that described in Example XIII but with catalysts containing 0.1% by weight of platinum in each case, catalyst No. 16 prepared through the use of ammonium hydroxide gave a reformat-e of 5.9 octane numbers higher than catalyst No. 17 prepared without the ammonium hydroxide medium and in the other case using chloroplatinic acid without ammonium hydroxide (catalyst 19) Different samples of the same gasoline were used as the charging stock for these reforming operations. The reforming in both cases was effected at a temperature of about 850 F., a pressure of 500 pounds per square inch and a space velocity of 2, in the presence of hydrogen in a molal ratio to hydrocarbon of about 3.2.

With platinum concentration of 0.3 by weight in each case, catalyst No. 18 prepared through the use of ammonium hydroxide gave a reformate having an F1 clear octane number of 86.2. Catalyst N0. 19 prepared without the ammonium hydroxide gave an F1 clear octane number of 80.4 Thus it is seen that the use of ammonium hydroxide resulted in a reformate of 5.8 octane numbers higher than the catalyst prepared without the ammonium hydroxide.

. 1 1- .EXAMPLE XV In another series of reforming runs in a manner similar to that described in Example XIV but with catalysts containing 0.1% by weight of platinum in each case, catalyst No. 20 prepared through the use ofammonium hydroxide gave a reformate of 5.9 octane numbers higher than cat alyst No. 21 prepared without the ammonium hydroxide.

I claim as my invention:

1. A method of manufacturing a catalyst which comprises impregnating a porous support with a solution of a platinum compound in contact with a basic compound selected from the group consisting of basic'ammonium salts and organic amino compounds, and calcining the thus impregnated support.

2. A method of manufacturing a catalyst which comprises impregnating a porous support with a solution of a platinum compound in contact with a basic organic amino compound, and calcining the thus impregnated support.

3. A method of manufacturing a catalyst which comprises impregnating a porous support with a solution of a platinum compound in contact with an amine, and calcining the thus impregnated support.

4. A method of manufacturing a catalyst which comprises impregnating a porous support with a solution of a platinum compound in contact with an alkylene polyamine, and calcining the thus impregnated support.

5. A method of manufacturing a catalyst which comprises impregnating a porous support with a solution of a platinum compound in contact with an alkanol amine, and calciningthe thus impregnated support.

6. A method of manufacturing a catalyst which comprises impregnating a porous support with a solution of a platinum compound in contact with ammonium carbonate, and calcining the thus impregnated support.

'7. A method of manufacturing a catalyst which comprises impregnating a porous support with a solution of a platinum compound in contact with ammonium carbamate, and calcining the thus impregnated support.

8. A method of manufacturing a catalyst which comprises combining a halogen with'porous alumina in an amount of from about 0.1% to about 8% by weight of said alumina on a dry basis, forming the composite into particles, calcining said particles, impregnating the calcined particles with a solution of a platinum compound in contact with a basic compound selected from the .group consisting of basic ammonium salts and organic amino compounds, and calcinin the thus impregnated particles.

9. The method of claim 8 further characterized in that said basic compound is an amine.

10. A method of manufacturing a catalyst which com-prises commingling with porous alumina a solution of a platinum compound and a basic compound selected from the group consisting of basic ammonium salts and organic amino compounds, said platinum compound being in an amount to form a final catalyst containing from about 0.01% to about 1% by weight of platinum, and calcining the resultant mixture.

11. A method of manufacturing a catalyst which comprises combining a halogen with a porous support in an amount of from about 0.1% to about 8% by weight of said support on a dry basis, commingling therewith a solution of a platinum compound and a basic compound selected 19 from the group consisting of basic ammonium salts and organic amino compounds, said platinum compound being in an amount to form a final catalyst containing from about 0.01% to about 1% by weight of platinum, and calcining the resultant mixture.

12. The method of claim 11 further characterized in that said halogen comprises fluorine in an amount of from about 0.1% to about 3% by weight of the supcrt on a dry basis.

13. The method of claim 11 further characterized in that said halogen comprises chlorine in an amount offmmabout 0.2% to about 8% by weight of the support on a-drybasisJ- v 14. The method of claim 11 further characterized in that said support comprises silica; T

15. The method '01 claim 11 further character- 20 ized in that said support comprises silica and a metal oxide. V

VLADIMIR HAENSEL. REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 1 Number Name Date 2,479,109 Haensel Aug. 16, 1949 2,479,110 Haensel Aug. 16, 1949 FOREIGN PATENTS Number Country Date 13,297 'Great Britain Sept. 14, 1916 188,503 7 Germany Sept. 27, 1907 

1. A METHOD OF MANUFACTURING A CATALYST WHICH COMPRISES IMPREGNATING A POROUS SUPPORT WITH A SOLUTON OF A PLATINUM COMPOUND IN CONTACT WITH A BASIC COMPOUND SELECTED FROM THE GROUP CONSISTING OF BASIC AMMONIUM SALTS AND ORGANIC AMINO COMPOUNDS, AND CALCINING THE THUS IMPREGNATED SUPPORT. 